The invention relates to a method for operating an environment-monitoring system for a motor vehicle, by means of which the positions of objects in the environment laterally adjacent to and also in front of and behind the vehicle are determined.
Document DE 101 07 219 A1 relates to a method for operating an adaptive driving-speed control system for a motor vehicle. The adaptive driving-speed control system includes a central control unit to which speed data and spacing data are communicated from a radar sensor. The document makes reference to a method and an apparatus for recognition of maladjustment in a motor vehicle. In this case electromagnetic waves are emitted, and the electromagnetic waves reflected from a stationary object are received and evaluated; the signals that are capable of being evaluated are the relative angle and a relative spacing between the detected stationary object and a reference axis of the motor vehicle, as well as a relative velocity between the detected stationary object and the motor vehicle; subsequently, on the basis of the relative angle and the relative spacing between the motor vehicle and the detected stationary object, and also on the basis of a vehicle-specific velocity, a correction value for the relative angle is determined.
Document DE 43 39 371 A1 relates to a detection method for registering a horizontal error between a scan centre line and the travel-direction line of a vehicle during straight-ahead driving. With this method, a computer registers a change of position of a reflector that has been provided at the left edge of a road. A further computer derives a location of the reflector, which represents a spacing between the reflector and the vehicle and a direction of the vehicle from the reflector.
Document DE 10 2006 045 165 A1 relates to a driving-assistance system for motor vehicles, with an angle-resolving position-finding sensor and with a locking and unlocking device for disabling and enabling an assistance function. The driving-assistance system includes an angle-resolving position-finding sensor and an electronic data-processing system which evaluates the data supplied by the position-finding sensor, and on this basis performs one or more assistance functions. In the data-processing system a correction module has, in addition, been implemented, with which any faulty adjustment, i.e. a maladjustment angle, of the position-finding sensor can be established during operation of the driving-assistance system. An independent algorithm for determining the maladjustment angle is based on the evaluation of apparent transverse motions of stationary objects at the edge of the roadway, which are simulated by the maladjustment of the sensor.
Document EP 1 286 177 A1 relates to the registering of an occurrence of an axial displacement in a horizontal direction in the case of a radar mounted on a vehicle, the determining of the degree of axial displacement in the horizontal direction, and the correction of the axial displacement in the horizontal direction. In this connection an FM-CW radar radiates a radio wave in the forward direction of the vehicle and calculates the spacing from a target located in front of said vehicle, and the relative velocity thereof.
It is already known to employ environment-monitoring systems in modern motor vehicles. The most important components of an environment-monitoring system are sensors that register the range, the angular position and the relative velocity of objects in the environment laterally adjacent to and also in front of and behind the vehicle in question. Since the greatest efficiency when determining the position of objects above all, in bad weather is obtained by means of radar sensors, here the designation ‘environment-monitoring system’ is to be regarded as synonymous with the designation ‘radar system’.
By means of environment-monitoring systems, inter alia the following functions are realised with a view to enhancing the driving safety.
In the case of adaptive speed control (ACC, adaptive cruise control), the positions of vehicles travelling ahead of the vehicle in question are registered, in order to adapt the speed of the vehicle in question to changing traffic conditions automatically by self-acting accelerating, easing off the throttle, or braking. Hence an ACC system permits the maintenance of a spacing, depending on speed, of the vehicle in question from a vehicle in front. An ACC system has been described in WO 2004/045888 A1.
In the case of a collision warning system (FCW, forward collision warning), in addition to an ACC system the driver is warned of critical spacing situations and, by automatic partial braking, is assisted in shortening the stopping-distance. In the case of an automatic emergency braking system (AEB, automatic emergency braking), furthermore collisions can even be avoided entirely in the ideal case. An FCW or AEB system has been described in WO 2012/062451 A1.
In the case of a lane-change assistance system (LCA, lane change assistant), the positions of vehicles travelling behind and laterally adjacent to the vehicle in question are registered, in order to warn the driver about vehicles in the blind spot adjacent to his/her own vehicle, and about vehicles that are located in a region adjacent to or behind his/her own vehicle that is critical for a change of lane. An LCA system has been described in DE 10 2010 054 221 A1.